With the development of science and technology, it's a trend to design a metal housing as the housing for a terminal. When designing a metal housing for a terminal, it may be usually designed to have a three-piece structure such that the metal housing would not affect terminal antennas transmitting and receiving signals normally. FIG. 1 illustrates a back view of a three-piece terminal housing, the metal housing is divided into three parts, and “blank band” gaps are existed between the three parts as signal outlets, such that the antennas may transmit or receive signals via the signal outlets. However, the metal housing with the “blank band” gaps is not a truly all-metal housing, which affecting the beauty of the terminal.